Change internals of FILE: reuse the unget buffer field to access an

extended attribute data structure (pimpl idiom). Idea taken from citrus.
Much discussion with deraadt@, otto@, millert@...

This is the least disruptive way to extend FILE, since its size can't really
change without this being a flag day. So the size doesn't change.

Actual additions to the structure will come in separate steps, since this
change is nasty enough on its own.

Tests by otto@ and others, careful reading of code by otto@ and millert@.

This is definitely a major bump, and has been checked to not impact a
full ports build.

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/libc/stdio/vsprintf.c b/lib/libc/stdio/vsprintf.c
index 8e4b6809127..958a12e8b67 100644
--- a/lib/libc/stdio/vsprintf.c
+++ b/lib/libc/stdio/vsprintf.c
@@ -31,11 +31,12 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char rcsid[] = "$OpenBSD: vsprintf.c,v 1.9 2004/09/28 18:12:44 otto Exp $";
+static char rcsid[] = "$OpenBSD: vsprintf.c,v 1.10 2005/04/30 09:25:17 espie Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <stdio.h>
 #include <limits.h>
+#include "local.h"
 
 #if defined(APIWARN)
 __warn_references(vsprintf,
@@ -47,7 +48,9 @@ vsprintf(char *str, const char *fmt, _BSD_VA_LIST_ ap)
 {
 	int ret;
 	FILE f;
+	struct __sfileext fext;
 
+	_FILEEXT_SETUP(&f, &fext);
 	f._file = -1;
 	f._flags = __SWR | __SSTR;
 	f._bf._base = f._p = (unsigned char *)str;